Frame for a Rohloff?

[Andy in Sig]

Does anybody know what are the best drop out arrangements for a Rohloff hub gear? As a complete innocent in this field I would have thought a backward pointing vertical arrangement but then getting the chain on would be a bugger unless you had an excentric bottom bracket arrangement. I seem to recall seeing a picture in a German mag of spring loaded steel plates which locked it into position. I guess (and it is a guess) that the biggest factor is the one sided pull on the hub which would take it out of true if it weren't held securely in place.

The question is important because if you get a flat, you want to be confident that you can remount the wheel in a true position.

 

[Steve Austin]

Nicolai seem to have got the design pretty sorted. check their website

 

[Andy in Sig]

Thanks. I'll have a look. I suppose what I really need to do (just to satisfy my thirst for knowledge) is check out the theory of drop outs.

 

[Andy in Sig]

I've just had a look. I remember now reading a review of that Argon TR with Rohloff and the carbon drive belt instead of a chain. Brilliant design - especially the bit where the rear drop out is openable to get the belt off - and it looks like being as near as you can get to a maintenance free bike.

 

[betty swollocks]

My Thorn Tour does it pretty well.
Chain tension is taken care of with an eccentric b/b axle.
The drop outs are vertical, with an elongated one for for the hub's mini torque arm to slot into.
The cables from the twist grip shifter are routed via a stop attached to the l/h brake boss and connect to two cables coming from the hub, with bayonet connectors.
Dropping the wheel in and out is a absolute cinch!

 

[Andy in Sig]

That sounds interesting. Do Thorn sell just frames?

 

[PpPete]

They make complete bikes too
http://www.thorncycles.co.uk/models.html
Doesn't look like they make a 700c wheel model for Rohlhoff hub.

 

[betty swollocks]

they have pdf file about living with a Rohloff which can be downloaded here.

and yes. they sell Rohloff-specific frames here.

 

[Andy in Sig]

Thanks for those. Both my bikes have got Rohloffs but the frame on one of them was designed for normal derailleurs (the other is a recumbent) and I was thinking of shifting the Rohloff to a specific frame. Maybe the Thorn ones will be the business.

 

[Cranky]

You may also find this of interest - contains some info on dropouts.

 

[Piemaster]

Bit more info on Bob Jackson site too

 

[Piemaster]

Thorn have a frame on ebay with a large picture that shows their dropouts quite well. here

 

[Greenbank]

http://www.vannicholas.com/ do Titanium frames designed for Rohloff (the Amazon and Zion).

The Amazon Rolhoff frame is €1199 (that's 1199 Euros).

 

[andrew_s]

To use a Rohloff, there are two issues to be addresses: Chain tension and Torque reaction.

Chain Tension:
a) A chain tension device, as used when running an MTB as singlespeed
Eccentric bottom bracket. Do you have to adjust your saddle after adjusting chain tension? Can you adjust chain tension with the chainset in place?
c) Adjustable rear dropouts. These are a vertical dropout in a sliding frame mount. There's probably 4 bolts to tighted/loosen, you've got to get both adjusted the same amount, and you may have to adjust your brakes. Rohloff's version has the disc mounts on the sliding part so you don't.
d) Horizontal standard dropouts or track ends. You'd need to use a torque arm rather than one of the tidier methods.

Torque reaction
a) A torque arm that attaches to a fitting on the chainstay, either a braze-on or a Rohloff fitting jubilee clipped on.
B) a short arm bolted to the disc brake mounts. Allen key needed to remove wheel.
c) an open fork that a bolt in an unused disc brake mount slots into.
d) a block that g0es in a LG dropout with a long slot. Standard hoorizontal dropouts & track ends won't be long enough for this and chain tensioning, and may not be strong enough.

With a standard frame, you need a chain tensioner and a torque arm fitting on the chainstay (Rohloff's is quick release).
For dedicated Rohloff frames, it seems to be a 50/50 split between eccentric BBs and sliding dropouts.